One purpose is to examine behavioral and biological consequences of prematurity and small-for-gestational-age, two factors which are known to place the human infant at risk. We will also use the rat and rabbit as animal models of prematurity and small-for-gestational-age to allow us to do experimental investigations of these phenomena. For both the human and animal species we will obtain directly comparable measures during the neonatal period of sleep-wake behavioral states and spontaneous motor activity. The human infants will be assessed on a variety of behavioral and medical measures through one year of age. The rat and rabbit will be studied for behavioral and biological functions through adulthood. A second purpose is to test out three models which may be predictive of future medical disturbances, including the possibility of being able to predict which infants may be at risk for the Sudden Infant Death Syndrome. These models are based upon a pattern of behaviors which include disorganized behavioral states and aberrant respiration patterns. We anticipate that our new measure of spontaneous activity will increase the predictive capability of these models. It is our hypothesis that through highly refined and quantitative measures of behavioral states, respiration, and activity patterns during the early days of life, it should be possible to make predictions of subsequent behavioral organization and dysfunction. We wish to chararcterize known dysfunctions and to predict unknown dysfunctions. For this reason, we will keep all of our raw data stored for a period of two years so that we may go back to the original records to identify patterns obtained during the neonatal period whenever we find evidence of dysfunction in any of the infants who were apparently normal at birth. Our objectives, therefore, are (1) to try to predict behavioral dysfunction through our measures during the neonatal period independent of standard clinical indices, and (2) to try to better understand the nature of the dysfunction through analytical procedures and through the use of our animal models. BIBLIOGRAPHIC REFERENCES: Denenberg, V.H., Gartner, J., and Myers, M. Absolute measurement of open-field activity in mice. Physiol. Behav., 1975, 15, 505-509.